Classification
D - World History
38
R - Medicine
28
B - Philosophy, Psychology, Religion
16
F - General American History
16
P - Language and Literature
10
Q - Science
9
H - Social Science
5
M - Music
5
L - Education
4
T - Technology
4
A - General Works
3
C - Historical Sciences
2
Z - Library Science
2
N - Fine Arts
1